Since he decided to step out as a leader, Donny McCaslin's been pretty busy: 2008's Recommended Tools showed Dave Douglas' former tenorman can walk the high wire of the sax-trio date, and he demonstrated a major ability to handle large units on the 2009 release Declaration. With Perpetual Motion, McCaslin attempts to do what a lot of great musicians strain to do: Have fun!

The opener "Five Hands Down" makes no bones about it: McCaslin's here to chew bubblegum and kick ass, and he's all out of bubblegum. Drummer Antonio Sanchez and bassist Tim Lefebvre lay down a monster riff that clears a wide swath for McCaslin's entrance, which changes the tone in the best kind of way. His tone is amazing as he drops notes and runs hither and thither, and Adam Benjamin's Fender Rhodes adds savory sauce in both solo and counter. As great as McCaslin's opening solo is, his performance on the rideout is stratospheric, with a passion that can only be measured on a Richter scale.

Perpetual has a marvelously organic feel about it. Almost every track has a sense of "Let's see where this goes." It's all about the groove on "Energy Generation," with Sanchez bringing the atomic energy he's capable of; his two-hander with McCaslin on the first four minutes of "Claire" is so wondrous, it's actually disappointing when the rest of the band joins in. The tone poem "Firefly" is both a reflective moment and an alternate soundtrack to one of the best TV shows that ever died, and Lefebvre's funny foundation riff on "L.Z.C.M." overcomes the work of drummer Mark Giuliana, who is steady and workmanlike but no replacement for Sanchez.

Producer David Binney breaks out his alto sax to help steam up "Impossible Machine," and intersperses hit-and-run electronics throughout the disc. I wish Binney had taken notes on this session, because then his latest disc Graylen Epicenter might not have been such a leaden affair. Perpetual Motion adds to the good work Chris Potter Underground and Benjamin's group Kneebody are doing to reclaim fusion for this generation. It also makes Donny McCaslin even more interesting than before, and that's saying something. Let's hope he stays busy, because this is really fun to watch.